Field of Invention
The present invention relates to a lens system, and more particularly to an imaging lens system.
Description of Related Art
Endoscopes generally include a series of lenses used to convey an image of a scene viewed from a distal end of the endoscope to a proximal end, where an image sensor may capture the image. Some mucus, such as gastric juice or chyme may exist in the environment where the endoscopes are used. For protecting the lenses from contamination and ensuring the light entrance, the endoscope includes a cover glass between the lenses and the scene, so that the mucus in the scene/environment can be blocked by the cover glass and light can travel through the cover glass toward the lenses.
However, the cover glass may not coordinate with the lenses effectively. For example, a portion of light passing through the cover glass may not pass through the lenses. Also, due to the size of the cover glass and the distance between the lenses and the cover glass, the endoscopes may have a long length and a long width that are disadvantage to the miniaturization of the endoscopes. Therefore, there is a desire to modify the configuration of the cover glass and the lenses.